EP1589562A2 - Plasma reactor for surface modification of articles - Google Patents

Abstract

In a processing chamber (1) there are plasma zones each with associated first (2) and second (3) sources of plasma/remote or downstream sources of plasma, past which substrates (4) can be run and the substrates are subjected to processing gases chemically activated by plasma in one of the sources.

Description

The invention relates to a plasma reactor for surface coating or - modification of objects or substrates with plasma process in a process chamber, preferably at reduced pressure as a vacuum process, with a Entrance lock to the process chamber, as well as an exit lock.

Usually, plasma reactors come in process chambers, For example, in semiconductor technology for the coating of Wafers or other semiconductor structures and other substrates by using the substrates, e.g. Wafer, over an input lock is introduced into the process chamber, wherein after introduction into the process chamber a for the subsequent coating or processing process suitable pressure is generated by a vacuum pump. As soon as the required pressure, for example, at 0.1 - 0.2 mbar is reached, the plasma reactor, for example, a capacitive electrode with a high frequency source activated by an appropriate through this High frequency energy is introduced into the electrode. At the same time, a suitable gas is introduced into the process chamber initiated.

By applying the high-frequency energy to the electrode the process gas is ionized in the process chamber and the in the process chamber (also referred to as recipient) Process material exposed to the plasma. During the treatment process is continuously fed fresh process gas and at the same time polluted or used gas aspirated.

After processing the substrate in the process chamber This is via an exit lock, in the first of the normal ambient pressure is set, handed over to the outside. At the same time, the exit lock ensures that that no process gases can enter the environment.

It is well known that in coating processes in a processing chamber, e.g. a vacuum chamber, always also the inner walls of the chamber as well as the plasma source even be coated with. These coatings can be after the previously known state of Do not prevent technology. The result is that productivity such a plant by the parasitic (unwanted) Coatings on the plasma source or the other Components of the process chamber is restricted. at Achieving a given boundary layer thickness must this Deposits are removed.

According to the prior art, for example, as common in microelectronics, the process chamber after reaching the boundary layer thickness at the plasma source and the others In situ components by etching, e.g. Plasma etching, cleaned. Alternatively, the process chamber can be natural also ventilated, opened and then mechanically cleaned.

A disadvantage of both methods, however, is that the Productivity of the system is not insignificantly limited is, as carried out during the cleaning no coatings can be.

The invention is therefore based on the object, a plasma reactor to create, while maintaining high productivity a quick, easy and selective cleaning of the Plasma sources and adjacent areas of the process chamber is possible.

The object underlying the invention is in a Plasma reactor of the type mentioned solved by that in the process chamber several, but at least two Plasma zones each provided with associated plasma sources are, with the substrates of the plasma sources over passable are and by the plasma at least one of the Plasma sources exposed chemically activated process gases and that at least one of the plasma sources is selected selectively from the substrates to be processed and the process chamber isolable are and that the isolated plasma sources and the surrounding region of the process chamber an etching gas can be fed.

Thus, the process chamber and the plasma reactor of parasitic Impurities are freed without the process chamber to open for external cleaning, or for the duration of an in situ etching the production (coating or surface modification).

In a first embodiment of the invention are for the insulation individual plasma sources provided seals, for example, as linearly displaceable slide, or in the case of linear plasma sources in front of the plasma source pivotable shields can be formed.

If pivotable shields are provided in front of the plasma source, It is beneficial if the shield when not in use is pivotable behind the linear plasma source.

For longitudinally extended plasma sources, the shield is each plasma source preferably from cylinder segments.

Alternatively or additionally, it may be provided that the Isolation of individual plasma sources by means of a suitable gas guide in the process chamber, for example between the isolated plasma source and the other plasma sources a pressure difference is generated.

With the solution according to the invention, it is possible to carry out an in-situ etching single plasma sources to eliminate parasitic To allow coatings while doing so the treatment of the substrates with other plasma sources to put. An interruption of the treatment process of Substrates for cleaning etching is no longer necessary. That means a significant productivity gain.

The substrates pass through several, at least in the process chamber but two plasma zones in which they through the Plasma are exposed to chemically activated process gas. In In each zone, the plasma source can be detected by a suitable device be isolated from the substrates.

Subsequently, the isolated plasma source instead of the Process gases are supplied to etching gases, so that then by plasma etching with the help of the etching gases, a cleaning of the plasma source and the surrounding areas in the process chamber of the parasitic coatings can be done.

During this process, the substrates can be attached to this Plasma source to be passed over without the etching gases can act on the surface. The coating or Treatment of the substrates then takes place through the other (s) Plasma source (s).

Will achieve the required layer growth rates several plasma sources are connected in series on the substrates, so, if necessary, at any time one or several plasma sources are etched without the Throughput of the substrates to affect.

The process-related division of a process chamber (vacuum chamber) in different zones is known per se. So be in an arrangement called a plasma box in one Vacuum chamber simultaneously layers of different composition produced.

However, it is essential to the invention here that each plasma source without appreciable interruption of the throughput of substrates between the two operating states - deposition or Etching - can be switched. The isolation takes place the substrates and the free etching (cleaning) without change the location of substrate to electrode, with some displacement e.g. the electrode within the process chamber is possible.

Fig. 1:

eine schematische Darstellung von zwei nebeneinander in einer Prozesskammer angeordneten Plasmaquellen sowie darunter vorbei geführten Substraten, sowie einem Schieber, links in geöffneter und rechts in geschlossener Position;

Fig. 2:

eine Variante der Erfindung, bei der die Reinigung mit beliebigen Remote- oder Downstream-Plasmaquellen erfolgt, wie z.B. induktiv gekoppelte oder auch Arcjet-Quellen; und

Fig. 3

eine schematische Darstellung von zwei nebeneinander in einer Prozesskammer angeordneten Plasmaquellen mit darunter vorbei geführten Substraten, sowie einer schwenkbaren Abschirmung, links in geschlossener und rechts in geöffneter, also hinter die Plasmaquelle geschwenkter Position.

The invention will be explained in more detail below using an exemplary embodiment. In the accompanying drawing figures show:

Fig. 1:

a schematic representation of two juxtaposed in a process chamber plasma sources and including passing past substrates, and a slider, left in the open and right in the closed position;

Fig. 2:

a variant of the invention, wherein the cleaning with any remote or downstream plasma sources, such as inductively coupled or Arcjet sources; and

Fig. 3

a schematic representation of two juxtaposed in a process chamber plasma sources with guided underneath substrates, and a pivotable shield, left in closed and right in open, so pivoted behind the plasma source position.

From Fig. 1 is a schematic representation of two side by side in a process chamber 1 arranged plasma sources 2, 3 as well as with guided past passing substrates 4. The substrates 4 are located at a distance side by side on a substrate carrier 5, which under the Plasma sources 2, 3 is passed over. The plasma sources 2, 3 are each within housings 6, 7, the may consist of quartz glass or metal. These shields 6, 7 are with feeders 8, 9 for process gases and provided for etching gases, with each of which the respective operating state process gases or etching gases fed are. The plasma sources 2, 3 are each not with represented high frequency sources connected to each required plasma 10, 11 to generate. Farther is the process chamber 1 with a vacuum pump, not shown connected to generate the necessary vacuum.

Furthermore, under each housing 6, 7 between the plasma source 2; 3 and the substrates 4 guidable slide 12, 13th provided with which the respective plasma space largely is separable from the remaining areas of the process chamber, so that the plasma 11 can not reach the substrates 4.

Fig. 1 left shows the plasma source 2 with associated plasma 10 in the coating state and on the right the plasma source 3 in the closed state during the cleaning etching.

Fig. 2 shows a schematic representation of the invention designed process chamber 1 using any Remote or downstream plasma sources 14 with feeders 8, 9 for process or etching gases. The drawing left part (Figure 2a) shows the remote or Downstream plasma source 14 with associated plasma 10 in the coating state and right, the remote or downstream plasma source 14 in the closed state (Fig. 2b) during of the cleaning etch.

Fig. 3 shows a specific embodiment with linear plasma sources 15, 16 each within a housing 6, 7, wherein in contrast to the previous explanations on shielding of the plasma 10, 11 from the substrates 4 on the Substrate carrier 5 rotary valve 17, 18 are provided.

On the left side of FIG. 3 is the Rotary valve 17 in the closed, so the cleaning position shown and on the right side according to the drawing in open position.

The invention is also suitable for such plasma reactors, in which, for process engineering reasons, multiple plasma sources 2, 3; 14; 15, 16 are arranged side by side to get up To produce the substrates, for example, a multi-layer structure. Are here all the housing 6, 7 according to the invention equipped, so can without interrupting the coating process individual plasma sources separated and in situ getting cleaned.

LIST OF REFERENCE NUMBERS

1

process chamber

2

plasma source

3

plasma source

4

substratum

5

substrate carrier

6

casing

7

casing

8th

feeding

9

feeding

10

plasma

11

plasma

12

pusher

13

pusher

14

Remote or downstream plasma source

15

linear plasma source

16

linear plasma source

17

rotary vane

18

rotary vane

Claims (8)

Plasma reactor for surface coating or modification of objects or substrates with plasma processes in a process chamber with plasma sources, preferably at reduced pressure as a vacuum process, with an entrance lock to the process chamber , and an exit lock, characterized gekennzei chnet that in the process chamber (1) more, at least however, two plasma zones are provided, each with associated plasma sources (2, 3; 15, 16), the substrates (4) being at the plasma sources (2, 3, 10, 11, 15, 16) or remote or downstream plasma sources (14) can be guided past and while the process gases are chemically activated by the plasma of at least one of the plasma sources (2, 3, 15, 16) and the remote or downstream plasma sources (14) and at least one of the plasma sources (2 , 3; 14; 15, 16) are selectively isolatable from the substrates (4) and the process chamber (1) to be processed, and that the isolated plasma source (s) (2, 3, 14, 15, 1, 6) and the surrounding region of the process chamber (1) an etching gas can be supplied. Plasma reactor according to claim 1, characterized in that seals are provided for the isolation of individual plasma sources (2, 3; 14; 15, 16). Plasma reactor according to claim 2, characterized in that slides (12, 13) are provided for the isolation of the plasma sources (2, 3; 14; 15, 16). Plasma reactor according to claim 2, characterized Porsche Style nzeichnet that is provided for the isolation of linear plasma sources (15, 16) each one in front of these pivotable rotary valve (17, 18). Plasma reactor according to claim 4, characterized Porsche Style nken characterized in that the rotary valve (17, 18) when not in use behind the linear plasma source (15, 16) is pivotable. Plasma reactor according to claim 4 and 5, characterized in that the rotary valves (17, 18) of each linear plasma source (15, 16) consists of cylinder segments. Plasma reactor according to one of Claims 1 to 6, characterized in that the isolation of individual plasma sources (1, 2, 10, 11, 15, 16) takes place by means of a suitable gas guide in the process chamber. Plasma reactor according to one of Claims 1 to 7, characterized in that a pressure difference exists between the respectively isolated plasma source (2, 3; 14; 15, 16) and the other plasma sources (2, 3; 14; 15, 16).

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